Inconel® studs, like Inconel 600, 601, 625, 686, 718 & 725 studs, are a family of nickel-chromium-molybdenum alloys used for their high strength at elevated temperatures and good corrosion resistance. Because of its high thermal stability, Inconel can be used in service temperatures ranging from cryogenic to 2200°F (982°C). The high alloy content of Inconel studs enable it to withstand a wide variety of severe corrosive environments. In mild environments, such as the atmosphere, sea water, neutral salts, and alkaline media, there is almost no attack to Inconel studs. In more severe corrosive environments the combination of nickel and chromium provides resistance to oxidizing chemicals, whereas the high nickel and molybdenum contents supply resistance to nonoxidizing environments.

Because Inconel studs offer a good balance of corrosion resistance, temperature stability, toughness and strength they are often a material of choice for chemical processing, aerospace, marine, electronics and oil & gas.

The most common grades of Inconel fasteners and flanges are Inconel 625 and Inconel 718. Gain more insight on these two grades by accessing our Inconel 625 and Inconel 718 overviews or by contacting our engineering experts.

Common Inconel Bolt Grades

Inconel 600

Alloy 600, UNS N06600, is a nickel-chromium alloy with good carburization and oxidation resistance through 2000°F. The alloy has long been used in the heat treating industry and Inconel 600 has useful resistance to dry Cl2 and HCl gases at moderately elevated temperatures.

Inconel 601, UNS N06601, is highly resistant to oxidation through 2200°F even under severe thermal cycling. The alloy has good high temperature strength, and retains its ductility after long service exposure. Inconel 601 alloy has good hot corrosion resistance under oxidizing conditions.

Inconel 625, UNS N06625, is the workhorse of the Inconel family and is one of the most common grades. It exhibits high creep-rupture strength and is oxidation resistant to 1800°F (982°C). Inconel 625 has excellent resistance to hot seawater, scrubber environments and reducing acids and this alloy resists a wide range of severely corrosive environments and is especially resistant to pitting and crevice corrosion.

Alloy 686, UNS N06686, is designed for outstanding corrosion resistance in a wide range of severe environments. The alloy is used in the most severe environments encountered in chemical processing, pollution control, pulp and paper production, and treatment of industrial and municipal waste.

Inconel 718, UNS N07718, is the most common grade of the hardenable Inconels. This precipitation-hardened nickel-chromium alloy combines outstanding corrosion resistance and high strength at elevated temperatures. The alloy is a about 2x as strong as Inconel 625 having excellent creep-rupture strength at temperatures to 1300°F (700°C) and usable up to 1800°F (982°C). Inconel 718 is often used in gas turbines, rocket motors, spacecraft, nuclear reactors, pumps, and tooling.

Alloy 725, UNS N07725, nickel-chromium-molybdenum-niobium age-hardenable alloy that has essentially the same corrosion resistance as Inconel 625, but with a strength of that is twice that of annealed Inconel 625. The strength of this alloy is developed by heat treatment to achieve high ductility and toughness. The alloy is resistant to hydrogen embrittlement and stress-corrosion cracking as well.

Incone X750

Alloy X-750, UNS N07750, is a precipitation hardened alloy known for its corrosion resistance and high temperature oxidation resistance up to temperatures of 1300°F. This alloy is similar to Alloy 600 but made precipitation hadenable with the addition of titanium and aluminium.